1. Field of the Invention
This invention lies in the field of water control valves. More particularly it concerns a float operated valve which permits water to trickle at a low flow rate into a tank when the water level is only slightly dropped below a selected level. However when the level is dropped more than a selected amount the valve opens farther to permit a high flow rate of water.
2. Description of the Prior Art
In the prior art as represented by my co-pending application Ser. No. 128,466, now U.S. Pat. No. 4,298,022, entitled, Energy Saver Control for Outdoor Water Heater and filed Mar. 10, 1980, now U.S. Pat. No. 4,298,022, a float valve is utilized for opening or intitiating a flow of water into an outdoor tank. Means are provided for restricting the flow into the tank, so that in cold weather, particularly, a small trickle of flow is provided to maintain a turbulent surface of the water in the tank so as to minimize freezing. Thus as the water level is lowered in the tank, water flow is limited by appropriate means such as a needle valve, or an orifice, so as to flow at a minimum rate consistent with maintaining a clear water surface. However if it should be desired to fill the tank rapidly, then a manual operation is required, to open the needle valve or remove the orifice, in order to get a much higher flow rate.
In FIG. 3 of my co-pending application Ser. No. 128,466, now U.S. Pat. No. 4,298,022, a situation is shown in which there are two float-operated valves one which controls a low rate of flow when the water level is high and the other which controls a high rate of flow when the water level is much lower.
This invention is designed to provide both of these features, that is a low-rate of flow or a high-rate of flow, depending on the specific level of liquid in the tank, and this is done with one float-operated valve, whereas in my prior application, two floats and two float operated valves were required.